The present invention relates to fingerprinting of articles, and more particularly to techniques for fingerprinting an article prior to use of the article such that the use of the article is not impacted by the fingerprinting process.
Techniques have been developed for generating fingerprints for articles based upon the physical structure of the article. In one such technique, developed by Ingenia Technology Limited (ITL) located in London, United Kingdom (www.ingeniatechnology.com), a scanner is configured to scan one or more areas of an article using a light beam (e.g., a laser beam) and detect the scatter pattern of the light reflected from the scanned area of the article. The scatter pattern data is then used to generate a fingerprint or digital signature for the scanned article. Due to differences in the surface structure of the articles at the microscopic level, the light scatter pattern is generally different for different articles. As a result, the fingerprint generated for an article is highly distinctive of that article and can be used to identify or authenticate that article. ITL has developed scanners that are capable of generating fingerprints for articles such as paper sheets. A description of their technology is provided in PCT Publication No. WO 2005/088533, entitled “Authenticity Verification Methods, Products, and Apparatuses” filed Mar. 9, 2005 and published Sep. 22, 2005.
UK Patent Application GB 2417707A assigned to ITL describes techniques for using a scanner to obtain fingerprints or digital signatures for a sheet of paper as the paper is being printed. The digital signature obtained for a paper sheet is stored in a database with an image of what was printed on the paper sheet. Subsequently, the stored information is used to determine the authenticity of the paper sheet.
The fingerprint scans described above however tend to be slow due to the vast amount of data collection and processing involved in generating the fingerprints. The print speeds in a normal printer are usually however much higher than current technology allows for generating the fingerprints. For example, normal printers commonly run at a page every 2 seconds—this is roughly double the scan speed of conventional paper fingerprinting devices. Hence, applications which envision fingerprinting pages as part of the printing process, as described in PCT Publication No. WO 2005/088533 and UK Patent Application GB 2417707A, are likely to be very slow due to the bottleneck of fingerprint scanning and processing that occurs as part of the printing.